To get the firework effect I drew a rectangle tube, which looks like a regular firework. I then left some about 5 key frames between the starting point to the point where the firework startes to go off. Then i used the paint brush to draw different coloured lines comming out of the black tube. I inserted another keyframe and erased the lines and drew specks using the same colour as I used for the lines and placed them in different places to make it look like the firework was disappearing. For the last key frame i inserted i drew specks of colour on the floor and that was the end of the firework effect. Hope this helps :)
Melissa